28 replies to this topic

[Norton]

Hi there forum colleagues,

Well I think I found almost the perfect chalk for fitting things like bass bars, necks and bridges.

I started out using plan old white chalk that I retrieved from the score board in my dart cabinet. The problem is that white chalk is hard to see against "white" spruce or even maple. Then I discovered multicolored chalk at, of all places, the grocery store one day.

I decided to use a stick of purple chalk for fitting the bridge on my violin project and it worked great! It was way easier to see than the white chalk I'd been using and I got the bridge to fit perfectly in no time.

The only problem now is getting the purple color out of the spruce wood grain in my violin belly. I tried blowing the chalk out with compressed air followed by sand paper and more compressed air. I got most of it out, but there's still that tell-tale purple stain in the spruce.

Does anyone have any tricks up their sleeve for getting purple chalk out of spruce?

Best,

Jason

[Frederick Dale]

Hi there forum colleagues,

Well I think I found almost the perfect chalk for fitting things like bass bars, necks and bridges.

I started out using plan old white chalk that I retrieved from the score board in my dart cabinet. The problem is that white chalk is hard to see against "white" spruce or even maple. Then I discovered multicolored chalk at, of all places, the grocery store one day.

I decided to use a stick of purple chalk for fitting the bridge on my violin project and it worked great! It was way easier to see than the white chalk I'd been using and I got the bridge to fit perfectly in no time.

The only problem now is getting the purple color out of the spruce wood grain in my violin belly. I tried blowing the chalk out with compressed air followed by sand paper and more compressed air. I got most of it out, but there's still that tell-tale purple stain in the spruce.

Does anyone have any tricks up their sleeve for getting purple chalk out of spruce?

Best,

Jason

[Frederick Dale]

You might try "scubbing" the chalked area gently using a dry,soft bristled toothbrush.
Fred

[Conor Russell]

I'd avoid coloured chalk really. Apart from the problem removing the colour, I think they may be made a bit 'greasy' so that they're not too dusty, but I'm not sure, and that might effect the glueing.

German school chalk is good. It comes in square sticks, wrapped in paper, and isn't 'dust free'.

[Roger Hargrave]

I'd avoid coloured chalk really. Apart from the problem removing the colour, I think they may be made a bit 'greasy' so that they're not too dusty, but I'm not sure, and that might effect the glueing.

German school chalk is good. It comes in square sticks, wrapped in paper, and isn't 'dust free'.

I agree with these words. I did try coloured chalks way back when Julius Caesar was a boy, but I had similar problems. White German school chalk is the best, but not easy to find these days.

[James M. Jones]

I tried the blue too ...not so good....
Awhile back we talked about this ...
Apparently,sometime the manufactures use wax and other adjuncts to produce dustless chalk and to help it bind...Very good for art work.... not so good for glue joints....I went and bought three of the cheapest brands, tried them, kept the one I liked.

[Jerry Lynn]

second time tonight for me posting the same linke (other on the current bass bar thread) this is the ChalkI use, it's what used to be sold as "lecturer's chalk." I only use white.

[Conor Russell]

That looks very good Jerry, thanks. Is it plain soft chalk, with no binders?

[Jerry Lynn]

Very soft, plain and no binders. It almost comes off of the stick with the floppy brush I use to "groom" the area I'm using the chalk with.

[Conor Russell]

Many thanks again Jerry, I'd been looking for the German chalk and not able to find any. My last box lasted for years! This stuff sounds the same.

I roll the chalk sticks up in gummed brown paper tape, which I peel off as I use it. Keeps everything tidy and clean.

[Addie]

I used a microfiber dusting cloth. Worked well.

[Mat Roop]

I've used 4F pumice, but you need good lighting to see the pumice.... anything else negative about that?
Thanks, Mat

[Jeff White]

but you need good lighting to see the pumice.... anything else negative about that?

Just that (seeing the pumice). My biggest deal is seeing the chalk and not having it "build up" in an area to give a false reading. If I "sprinkle" it, I always have false readings (buildups). I usually just rub it onto the area not being changed, but notice that Jerry mentioned something to the affect of shaving powder from the chalk to the area??? jeff

[Jerry Lynn]

Just that (seeing the pumice). My biggest deal is seeing the chalk and not having it "build up" in an area to give a false reading. If I "sprinkle" it, I always have false readings (buildups). I usually just rub it onto the area not being changed, but notice that Jerry mentioned something to the affect of shaving powder from the chalk to the area??? jeff

The trick to seeing chalk is to not look at it with light coming directly on it from above. An oblique angle to a light source really helps. I don't shave the chalk off of the stick, I rub it on, however the chalk I use is so soft that I can "groom" it with a floppy brush



The chalk layer needs to be even and consistent, not too thick. With a patch the last final fittings are accomplished by grooming the chalk, placing the patch in the bed, lightly clamping (the same place, the same pressure every time) and lightly tapping on the patch (same place every time), and repeat.

[Doug Marples]

For me the visibility of plain white chalk is best when the light source is coming from behind me, over my shoulder. The tiny particles of chalk reflect back much more than the surface of the wood. In difficult situations it can help to mark the areas where the chalk has transferred with a soft pencil (while holding the work piece in the optimum lighting) then return the work piece to a more convenient position on the bench for removing the marked areas.

[Mountain Luthier]

I've brushed on blue chalk powder for "chalk lines".
Might be wax free. Satifactory results.

[Addie]

I've brushed on blue chalk powder for "chalk lines".
Might be wax free. Satifactory results.

That’s what I used too. The microfiber dusting cloth did a great job of getting rid of the blue.

[Johnmasters]

Hi there forum colleagues,

Well I think I found almost the perfect chalk for fitting things like bass bars, necks and bridges.

I started out using plan old white chalk that I retrieved from the score board in my dart cabinet. The problem is that white chalk is hard to see against "white" spruce or even maple. Then I discovered multicolored chalk at, of all places, the grocery store one day.

I decided to use a stick of purple chalk for fitting the bridge on my violin project and it worked great! It was way easier to see than the white chalk I'd been using and I got the bridge to fit perfectly in no time.

The only problem now is getting the purple color out of the spruce wood grain in my violin belly. I tried blowing the chalk out with compressed air followed by sand paper and more compressed air. I got most of it out, but there's still that tell-tale purple stain in the spruce.

Does anyone have any tricks up their sleeve for getting purple chalk out of spruce?

Best,

Jason

I also use blue chalk to set necks. Before gluing, I take most of it off with a pencil eraser. There is still some visible after varnishing, but eventually, it seems to fade and become invisible.

I never fit a bridge to a white violin. I use those deJacques bridges with swivel feet. They can be trimmed if you wish and they certainly seem to give a close approximation to a fitted bridge. To fit a bridge on a varnished violin, I locate the bridge and start off with carbon paper. After it is close, I use China marker, also called grease pencil.


For a bass bar, I devise a way to locate it and then slip carbon paper under it. I draw the carbon paper along the wood, not move the wood pieces. It works quite well. Before gluing, I clean both surfaces with xylene in case there is any wax etc in the black marks. I have never had a problem with the glue joint.

My dentist uses carbon paper, so I expect there is nothing much better.

[David Burgess]

My dentist uses carbon paper, so I expect there is nothing much better.

But dentistry needs to devise methods which will sorta work for the average person with only four years of specialized training. It’s crude compared to what the best restorers can do.
Heck, I needed to tell my dentist a gluing protocol to put an end to my crown coming loose repeatedly.

Need colored chalk to see what’s going on? Might go with the stuff which is white under ordinary light, and fluoresces various intense colors under UV light. It might even be said to help future evaluators find repairs, versus ordinary chalk.

Please don't fit your bass bars with sandpaper (from the "bassbar question" thread). It gives what seem to be good results, as long as one hasn't experienced better results.

[Johnmasters]

But dentistry needs to devise methods which will sorta work for the average person with only four years of specialized training. It’s crude compared to what the best restorers can do.
Heck, I needed to tell my dentist a gluing protocol to put an end to my crown coming loose repeatedly.

Yes, you are certainly correct. I think this goes for most practitioners in the medical business. Basically, most are just trained technicians. Way over-paid. Come to think of it, most Western violins are way over-priced.

You wear a crown ???